PROJECT SUMMARY/ABSTRACT My overall goal in this proposal is to address the current limitations in surgical options for bladder reconstruction while developing my professional abilities to transition into an independent investigator. My professional objective is to have a position as a lab director in a superb academic institution that will allow me to continue to expand the frontiers of regenerative medicine by creating innovative stem cell-based therapies for urological tissue reconstruction. My primary research training objectives will be to acquire new technical skills in urological tissue engineered systems and human pluripotent stem cell biology. This will be accomplished through additional fundamental coursework and hands on instruction in laboratory protocols and techniques as detailed in the aims of the proposal. Career development mechanisms will include instructive seminars and mentored guidance in grant writing, academic job interviewing, laboratory management, and manuscript preparation. An advisory committee will evaluate the completion of both my scientific and career development milestones and facilitate my transition into an independent investigator. Tissue engineering approaches for the urinary bladder have recently been developed utilizing 3D scaffolds seeded with autologous smooth muscle cells (SMCs). These strategies have led to partial restoration of organ functionality in short-term clinical trials. However, the efficacy of these constructs for complete defect repair may be limited by the suboptimal properties of conventional biomaterial carriers and availability of functionally competent cell sources. Silk-based biomaterials provide an exceptional combination of physical characteristics that are well suited to support bladder function and therefore may address limitations associated with current scaffold materials. Pluripotent stem cell populations such as embryonic stem cells (ESCs) and/or induced pluripotent stem (iPS) cells may fulfill the need for alternative cell sources capable of generating organ and patient-specific SMCs. In order to address the current limitations in bladder functional tissue engineering (FTE), we will challenge the overall hypothesis that: FTE modalities using silk-based biomaterials seeded with primary or stem cell-derived SMCs will promote smooth muscle defect consolidation and restoration of bladder function. The specific aims of the study are: Aim 1: Determine the efficacy of silk-based biomaterials seeded with primary SMCs for bladder smooth muscle tissue regeneration. Aim 2: Evaluate the utility of ESC and iPS-derived SMCs as cell sources for functional bladder tissue engineering.